hi folks. i'm building a site for my girlfriend's poems and i'm at my wits end here.
this is my third day learning css so bear with me please...

the image swapping works perfectly in IE, but looks very strange in firefox.??

the address is here: http://poettree.i8.com sorry for the banner ads, i'm moving it to it's own domain as soon as i can fix this problem. iv'e also been googling for literally a few days now, so any help is greatly appreciated!